function error = clicks_cal_error(params, data)
x0 = params(1);
kx = params(2);
y0 = params(3);
ky = params(4);
sum_errors = 0;
for index = 1:size(data,1)
    x = data(index,1);
    y = y0 + ky*tan((x-x0)/kx) ;
    sum_errors = sum_errors + (data(index,2)-y)^2;
end
error= sum_errors/size(data,1);